Distillate petroleum product and method of treating the same



Ptented May 15, 1934 UNITED OFFICE DISTILLATE PETROLEUM PRODUCT AND DIETHDD F TREATING THE SAME York No Drawing. Application June 25, 1930, Serial No. 463,824

13 Claims.

This invention relates to distillate petroleum products, more particularly gasoline and kerosene, and to a method of and means for imparting a stability thereto with respect to color, gum

formation and odor, and for removing any objectionable color developed therein during storage.

This application is a continuation-in-part of our co-pending applications Serial No. 395,192, filed September 25, 1929, and Serial No. 165,546,

filed February 3, 1927.

Heretofore we have discovered thatcertain organic compounds of the nature of negative oxidation catalysts have the property of preventing or materially delaying the formation of color, gum

and malodorous constituents in distillate petroleum products, particularly gasoline and kerosene. Notable amongst these compounds are the hydroxybenzenes, especially hydroquinone and pyrogallol. Certain of these compounds, particularly hydroquinone and pyrogallol, have the added property of decolorizing distillate petroleum products which have become discolored during storage.

We have found, however, that a number of these compounds will not function properly in the presence of water, due to the fact that they are considerably more soluble in water than in the distillate petroleum products. This characteristic materially affects the commercial value of these compounds as stabilizers and decolorizers, particularly when the treated distillates are handled in bulk. because of the difilculties, involved in maintaining tankers, storage tanks, pipe lines and delivery trucks free of water.

In accordance with the present invention, however, the decolorization and/or the stabilization of distillate petroleum products with regard to color, gum formation and odor may be readily and eil'ectually attained regardless of the presence of water, by the use of certain compounds, more soluble in the distillates and less soluble in water, than those previously used.

One of the objects of the present invention is to provide a method of and means for efiectually decolorizlng and/or stabilizing distillate petroleum products, particularly those of A. P. I. gravity higher than 37 degrees, with respect to color, gum formation and odor in the presence of water. V

Another object of the invention is to provide agents or compounds eifective in removing initial or recurrent discoloration of distillate petroleum products and for stabilizing the same as to color, odor and the formation of gum, which agents or compounds are more soluble in the distillates and less soluble in water than those previously used.

Among the compounds in the nature of negative oxidation catalysts that we have discovered are effective as decolorizers and stabilizers of dis- 00 tillate petroleum products with respect to color, gum formation and odor, whether in the presence of water or not, are the alkyl substituted hydroxybenzenes, especially methyl, ethyl, propyl and butyl pyrogallol. These compounds are formed 6 preferably by substituting alkyl groups for some of the hydrogens in pyrogallol, and are substantially insoluble in water but readily soluble in distillate petroleum products. For example, butyl pyrogallol is only thirty times more soluble in water than in kerosene, whereas pyrogallol is thirty thousand times more soluble in water than in kerosene.

A relatively minute amount, preferably less than 0.01% of the agent or compound may be thoroughly mixed with the distillate to be treated, although it will be understood that the distillate may be percolated through a mass of the compound, if desired. Preferably, however, the compound is first' dissolved in a suitable solvent which is miscible with the distillate, such as an aliphatic alcohol, particularly isopropyl alcohol, in the proportion of one part of the compound to approximately ten parts of the solvent. The resulting solution is then added to the distillate to be treated in minute amounts, preferably to such an extent that the distillate contains less than 0.01% of the compound. This method usually results in the compound being distributed throughout and dissolved in the distillate more readily than if it were added directly thereto.

' The results of the following tests will illustrate the effectiveness of the treatment of distillate petroleum products in accordance with our invention.

A sample of kerosene which had developed a color of minus 15, as measured by the Saybolt chromometer, was treated with one part of propyl pyrogallol to 25,000 parts of oil. After standing for one day the color of the treated oil im- 100 Gum con- Color Compound Oonceturation tent after after 6 6 months months Milliaram: Pyrogallol 1 to 72,600 30 4 Butyl pyrogallol 1 to 50,000"... 6 16 These results show that when pyrogallol and butyl pyrogallol are used inequal molecular quantities, the butyl pyrogallol is the more effective stabilizer and decolorizer, because of its greater solubility in the distillate.

While we have thus specifically described our invention, various modifications thereof may suggest themselves to those skilled in the art, and it therefore is our intention that the invention be limited only by the scope of the appended claims.

Having thus described our invention, what we claim and desire to secure by Letters Patent is:

1. A low boiling normally light colored distillate petroleum product of the class of gasoline or kerosene which normally tends to deteriorate by oxidation, as evidenced by the formation of color or gum therein during storage, having added thereto a small amount of an alkyl substituted .trihydroxy benzene suflicient substantially to retard the aforesaid deterioration, the alkyl group being substituted for hydrogen of the benzene nucleus.

2. A low boiling normally light colored distillate petroleum product of the class of gasoline or kerosene which normally tends to deteriorate by oxidation, as evidenced by the formation of color or gum therein during storage, having added thereto a small amount of an alkyl substituted pyrogallol sufficient substantially to retard the aforesaid deterioration, the alkyl group being substituted for hydrogen of the benzene nucleus.

3. A low boiling normally light colored distillate petroleum product of the class of gasoline or kerosene which normally tends to deteriorate by oxidation, as evidenced by the formation of color or gum therein during storage, having added thereto a small amount of a methyl substituted pyrogallol suflicient substantially to retard the aforesaid deterioration, the methyl group being substituted for hydrogen of the benzene nucleus.

4. A low boiling normally light colored distillate petroleum product of the class of gasoline or kerosene which normally tends to deteriorate by oxidation, as evidenced by the formation of color or gum therein during storage, having added thereto a small amount of an ethyl substituted pyrogallol sufficient substantially to retard the aforesaid deterioration, the ethyl group being substituted for hydrogen of the benzene nucleus.

5. A low boiling normally light colored distillate petroleum product of the class of gasoline or kerosene which normally tends to deteriorate by oxidation, as evidenced by the formation of color or gum therein during storage, having added thereto a small amount of a propyl llbstituted pyrogallol sufficient substantially to retard the aforesaid deterioration, the propyl group being substituted for'hydrogen of the benzene nucleus.

6. The method of stabilizing the characteristics of a low boiling normally light colored petroleum distillate product of the class of gasoline or kerosene that normally tends to deteriorate by oxidation, as evidenced by the formation of color or gum therein during storage, which comprises adding thereto, prior to substantial deterioration as aforesaid, a small proportion of an alkyl substituted trihydroxy benzene sufficient substantially to retard the aforesaid deterioration, the alkyl group being substituted for hydrogen of the benzene nucleus.

'7. The method of stabilizing the characteristics of a low boiling normally light colored petroleum distillate product of the class of gasoline or kerosene that normally tends to deteriorate by oxidation, as evidenced by the formation of color or gum therein during storage, which comprises adding thereto, prior to substantial deterioration as aforesaid, a small proportion of an alkyl substituted pyrogallol sufficient substantially to retard the aforesaid deterioration, the alkyl group being substituted for hydrogen of the benzene nucleus.

8. The method of decolorizing a normally light colored low boiling petroleum distillate product of the class of gasoline or kerosenewhich has become discolored by spontaneous color formation during storage, which comprises adding to said discolored product a small proportion of an alkyl substituted trihydroxy benzene suflicient to effect removal of a substantial proportion of the aforesaid discoloration, the alkyl group being substituted for hydrogen of the benzene nucleus.

9. The method of decolorizing a normally light colored low boiling petroleum distillate product of the class of gasoline or kerosene which has become discolored by spontaneous color formation during storage, which comprises adding to said discolored product a small proportion of an alkyl substituted pyrogallol sufiicient to effect removal of a substantial proportion of the aforesaid discoloration, thealkyl group being substituted for hydrogen of the benzene nucleus.

10. The method of decolorizing a normally light colored low boiling petroleum distillate product of the class of gasoline or kerosene which has become discolored by spontaneous color formation during storage, which comprises adding to said discolored product a small proportion of a methyl substituted pyrogallol sufficient to effect removal of a substantial proportion of the aforesaid discoloration, the methyl group being substituted for hydrogen of the benzene nucleus.

11. The method of decolorizing a normally light colored low boiling petroleum distillate product of the class of gasoline or kerosene which has become discolored by spontaneous color formation during storage, which comprises adding to said discolored product a small proportion of an ethyl substituted pyrogallol sufficient to effect removal of a substantial proportion of the aforehas become discolored by spontaneous color formation during storage, which comprises adding to said discolored product a small proportion of a propyl substituted pyrogallol suflicient to effect product of the class of gasoline or kerosene which removal of a substantial proportion of the aforesubstituted polyhydroxy benzene sumcient substantially to retard the aforesaid deterioration,

the alkyl group being substituted for hydrogen of the benzene nucleus.

JAMES B. RATHER. LESLIE C. BEARD, JR. ORLAND M. REIFE. 

